Line Noise

What is it?

The term "line noise" refers to
random fluctuations - electrical impulses that are carried
along with standard AC current. Turning on fluorescent
lights, laser printers, working near a radio station, using
a power generator, or even working during a lightening storm
can all introduce line noise into systems.

What can it do?

Line noise interference can result in many
different symptoms depending on the situation. Noise
can introduce glitches and errors into programs and files. Hard
Drive components can be damaged. Televisions and computer
screens can display interference as "static" or "snow," and
audio systems experience increased distortion levels.

What can be done?

Surge suppressors, Line conditioners and
UPS units include special noise filters that remove or reduce
line noise. The amount of filtration is indicated in
the technical specifications for each unit. Noise suppression
is stated as Decibel level (dB) at a specific frequency (kHz
or MHz). The higher the dB, the greater the protection.

Be wary of "surge/noise
suppressors" that don't provide this information. Some
surge suppressors (Such as the Tripp Lite Isobar suppressors)
take noise suppression to a new level with Isolated Filter
Banks. These special banks prevent line noise generated
from one device from traveling through the surge suppressor
to interfere with other equipment.

Using a laser printer (a notorious
source for line noise) connected to the same suppressor that
powers a computer will not endanger the computer.